WO2014075492A1

WO2014075492A1 - Mesh protection method and device

Info

Publication number: WO2014075492A1
Application number: PCT/CN2013/082589
Authority: WO
Inventors: 富森; 张媛媛
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-11-15
Filing date: 2013-08-29
Publication date: 2014-05-22
Also published as: EP2919405A1; EP2919405A4; EP2919405B1; CN103812686A

Abstract

Disclosed are a mesh protection method and device. The method comprises: an end node which is located at the downstream of a signal flow on a protected span sending automatic protection switching (APS) request signalling along at least one protection path of the protected span according to configuration information about the end node when it is detected that a fault occurs in the protected span; an end node which is located at the upstream of the signal flow on the protected span sending APS response signalling along a corresponding protection path after having received the APS request signalling, and the end node which is located at the upstream of the signal flow executing a corresponding bridging/switching operation according to configuration information thereabout; intermediate nodes which have received the APS response signalling executing a corresponding straight forward operation according to respective configuration information; and the end node which is located at the downstream of the signal flow and has received the APS response signalling executing a corresponding bridging/switching operation according to configuration information thereabout. The present invention can improve the protection switching performance of a mesh network, and enhance the fault resistance thereof.

Description

Method and device for mesh protection

The present invention relates to a protection switching technique for an optical transport network, and more particularly to a method and apparatus for mesh protection. Background technique

In the optical transport network, with the increase of access services, the network is developing towards more and more nodes and more and more complex network topology. Mesh network protection has become a hot spot in current technology. The implementation method of the mesh network protection in the prior art is mainly for the protection of the service, and needs to be switched on the upper and lower nodes of the service, and the implementation thereof is complicated. If there are many nodes in the network, the switching time is difficult to reach 50 ms (milliseconds). ) requirements. In addition, the end-to-end protection of the service, the protection path of the service needs to be pre-configured, and the endpoint of the service protection path and the end point of the working path are coincident. In this case, the number of times the network resists the fault is also limited, and the fault is resisted. The number of times is often related to the number of protection paths of the service, and as the number of protection paths increases, the resource utilization of the network will decrease.

Therefore, how to improve the protection switching performance and enhance the anti-fault capability is a key issue to be solved in the current mesh network protection. Summary of the invention

The embodiment of the invention mainly provides a method and device for mesh protection, which improves the protection switching performance of the mesh network and strengthens its anti-fault capability.

The technical solution of the embodiment of the present invention is implemented as follows:

The embodiment of the invention provides a method for mesh protection, the method comprising:

An end node located downstream of the signal stream on the protected span detects that the protected span occurs In the event of a failure, the automatic protection switching APS request signaling is sent along at least one protection path of the protected span according to the configuration information of the end node;

After receiving the APS request signaling, the end node located upstream of the signal stream on the protected span sends APS response signaling along the corresponding protection path, and the end node located upstream of the signal flow performs according to its configuration information. Corresponding bridging/switching operation; the intermediate node that receives the APS response signaling performs a corresponding through operation according to the respective configuration information; and the end node located downstream of the signal flow that receives the APS response signaling according to its own configuration information Perform the appropriate bridging/switching operations.

When an end node located downstream of the signal flow sends APS request signaling along multiple protection paths of the protected span, the end node located upstream of the signal flow selects a protection path that performs protection switching, and is sent along the selected protection path. The APS response signaling carries the reverse request RR, and the APS response signaling sent along the unselected protection path carries the unsolicited NR.

Before detecting the fault, the method further includes:

Configuring a node configuration information table for the nodes in the mesh network, where the node configuration information table includes: a related node ID, a corresponding high-order optical data unit HO ODUk port, a corresponding HO ODUk state, and a remote signaling;

Configure the spanning protection for the mesh network, configure at least one protection path for each protected span, and configure the shared mesh protection SMP configuration information table of the nodes in the mesh network. The SMP configuration information table includes: Protection ID PID, working port and PID routing;

The configuration information includes the configuration information table and an SMP configuration information table.

In the HO ODU of each span in the mesh network, half of the time slots are allocated as protected resources, and the other half of the time slots are allocated as protected resources.

The APS request signaling and the APS response signaling are delivered through the APS of the HO ODUk or the protected communication channel PCC overhead.

The end node located on the downstream of the signal stream on the protected span is detecting the protected span. When the barrier disappears, the end node starts a recovery waiting time WTR, and sends a WTR request along at least one protection path of the protected span, and the end node located upstream of the signal flow on the protected span receives the WTR request, and then responds RR, the end node located upstream of the signal flow and the end node located downstream of the signal flow are in a state of being switched until the WTR time expires;

When the WTR time expires, the end node located downstream of the signal stream sends an APS request signaling carrying the NR along the at least one protection path of the protected span according to its configuration information, which is the protected span The node that receives the APS request signaling carrying the NR on the protection path that performs the protection releases the corresponding port idle and answers the NR.

The embodiment of the present invention further provides a network protection system, including: an end node on a protected span, and an intermediate node on a protection path, where

An end node located downstream of the signal flow on the protected span, configured to send, according to the configuration information of the end node, at least one protection path along the protected span according to the configuration information of the end node when detecting that the protected span fails Automatic protection switching APS request signaling;

The end node located upstream of the signal stream on the protected span is configured to send the APS response signaling along the corresponding protection path after receiving the APS request signaling, and the end node located upstream of the signal flow according to its own The configuration information performs the corresponding bridging/switching operation;

The intermediate node that receives the APS response signaling is configured to perform a corresponding through operation according to the respective configuration information;

The end node located downstream of the signal stream that receives the APS response signaling is configured to perform a corresponding bridging/switching operation according to its configuration information.

When the end node located downstream of the signal stream sends APS request signaling along multiple protection paths of the protected span, the end node located upstream of the signal flow is configured to select a protection path for performing protection switching, and along the selected protection The APS response signaling sent by the path carries the reverse request RR, and the APS response signaling sent along the unselected protection path carries the unsolicited NR.

The configuration information includes a node configuration information table and an SMP configuration information table. The node configuration information table includes: a relevant node ID, a corresponding high-order optical data unit HO ODUk port, a corresponding HO ODUk state, and a remote signaling;

The SMP configuration information table includes: a protection identifier PID, a working port, and a PID route. In the HO ODU of each span in the mesh network, half of the time slots are allocated as protected resources, and the other half of the time slots are allocated as protected resources.

The end node located downstream of the signal stream on the protected span is further configured to: when detecting that the fault of the protected span disappears, initiate a recovery wait time WTR, and send along at least one protection path of the protected span The WTR request; the end node located upstream of the signal stream on the protected span receives the WTR request, and responds to the RR, and the end node located upstream of the signal flow and the end node located downstream of the signal flow are in a switching state until the WTR time expires;

The method and device for mesh protection provided by the embodiments of the present invention can improve the protection switching performance of the mesh network, strengthen the anti-fault capability, and at least resist two pipeline failures. DRAWINGS

1 is a flowchart of a method for mesh protection according to an embodiment of the present invention;

2 is a schematic diagram of a mesh network according to an embodiment of the present invention;

3 is a schematic diagram of resource division according to an embodiment of the present invention;

4 is a schematic diagram of a node ID configuration according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a span configuration according to an embodiment of the present invention; FIG.

FIG. 6 is a schematic diagram of service configuration according to an embodiment of the present invention; FIG. 7 is a schematic diagram of selecting a protection path to perform a request when processing a single direction fault according to an embodiment of the present invention; FIG.

FIG. 8 is a schematic diagram of a node bridging/switching operation according to an embodiment of the present invention; FIG.

FIG. 9 is a schematic diagram of a node through operation according to an embodiment of the present invention; FIG.

10 is a schematic diagram 1 of a service flow before and after protection switching according to an embodiment of the present invention;

FIG. 11 is a second schematic diagram of service flow before and after protection switching according to an embodiment of the present invention;

FIG. 12 is a schematic diagram 3 of a service flow before and after protection switching according to an embodiment of the present invention;

FIG. 13 is a schematic diagram of a request for selecting a protection path when processing two single-direction faults according to an embodiment of the present invention; FIG.

FIG. 14 is a schematic diagram of traffic flow after switching in two directions in a single direction according to an embodiment of the present invention; FIG.

FIG. 15 is a schematic diagram of requesting a request to two protection paths simultaneously when processing a single direction fault according to an embodiment of the present invention; FIG.

16 is a schematic diagram of requesting two directions of protection directions simultaneously when processing two single-direction faults according to an embodiment of the present invention;

FIG. 17 is a schematic diagram of processing when two faults in the direction are lost when one fault disappears according to an embodiment of the present invention; FIG.

FIG. 18 is a schematic structural diagram of a network protection system according to an embodiment of the present invention. detailed description

The technical solutions of the present invention are further elaborated below in conjunction with the accompanying drawings and specific embodiments. A method for mesh protection provided by the embodiment of the present invention, as shown in FIG. 1 , mainly includes: Step 101: An end node located downstream of a signal flow on a protected span detects that the protected span fails. And sending, according to the configuration information of the end node, the automatic protection switching (APS, Automatic Protection Switch) request signaling along the at least one protection path of the protected span. Preferably, when the end node located downstream of the signal stream sends the APS request signaling along the multiple protection paths of the protected span, the end node located upstream of the signal flow selects the protection path for performing protection switching, and is selected along the edge. The APS response signaling sent by the protection path carries a reverse request (RR), and the APS response signaling sent along the unselected protection path carries no request (NR).

Before detecting the fault, configuring a node configuration information table for the nodes in the mesh network, where the node configuration information table includes: a relevant node ID, a corresponding high-order optical data unit HO ODUk port, a corresponding HO ODUk state, and a remote signal. Order

Configure cross-segment protection for the mesh network, configure at least one protection path for each protected span, and configure a shared mesh protection (SMP) configuration information table of the nodes in the mesh network, in the SMP configuration information table. Includes: Protection ID (PID), Work Port, and PID Routing;

The APS request signaling and the APS response signaling are delivered through the APS or Protected Communication Channel (PCC) overhead of the HO ODUk.

Step 102: After receiving the APS request signaling, the end node located upstream of the signal stream on the protected span sends APS response signaling along the corresponding protection path, and the end node located upstream of the signal flow according to its own The configuration information performs a corresponding bridging/switching operation; the intermediate node that receives the APS response signaling performs a corresponding direct operation according to the respective configuration information; and the end node located downstream of the signal flow that receives the APS response signaling according to the The configuration information performs the corresponding bridging/switching operation.

The end node located downstream of the signal stream on the protected span detects that the fault of the protected span disappears, the end node initiates a recovery wait time (WTR), and at least one protection along the protected span The path sends a WTR request, and after receiving the WTR request, the end node located upstream of the signal stream on the protection span responds to the RR, and the end node located upstream of the signal flow and the signal flow The downstream end node is in the switching state until the WTR time expires;

A specific embodiment of the embodiment of the present invention will be described by taking a high-order (HO) optical data unit (ODU) mesh protection as an example. In the high-order ODU mesh network, mesh protection will be implemented in the following form:

1. In each HO ODU of the span, half of the time slots are allocated as protected resources, and the other half of the time slots are allocated as protection resources;

2. Each protected span is a subnet connection (SNC) protection unit;

3. After each protected span fails, it is switched to its preset protection path;

4. The protection trigger condition is the inherent detection fault or service layer fault of HO ODUk;

5. APS signaling is transmitted through HO ODUk's automatic protection switching (APS, Automatic Protection Switch)/protective communication channel (PCC, Protection Communication Control) overhead;

6. From the service point of view, the switching is a Wrapping method, and switching occurs at both ends of the HO ODUk;

7. The HO ODUk related to the protection resources should be directly operated.

In a physical network topology, the network working resources and the protection resources are first planned. As shown in Figure 2, some spans are planned into a HO ODU shared grid, and one HO ODU is configured on each span. Resources, where 0~1/2 time slots are used as protected resources, and 1/2~1 time slots are used as protection resources, as shown in Figure 3. Then configure the network node. The specific configuration method is as follows: Assign a node ID (NID) to each ODUk scheduling node, as shown in Figure 4. Each node must configure its own node configuration information table, with nodes F, J, K, and G as examples, configured for node F. The node configuration information table is shown in Table 1 below:

Table 1

The node configuration information table configured for node J is shown in Table 2 below:

HO ODUk port corresponding to the relevant node ID Corresponding to the HO ODUk status Remote signaling

06 j-i Idle NR

09 j-2 Idle NR

0b j-3 Idle NR

0e j-4 Idle NR

Table 2

The node configuration information table configured for node K is shown in Table 3 below:

0a k-1 Idle NR

07 k-2 Idle NR

0c k-3 Idle NR

table 3

The node configuration information table configured for node G is shown in Table 4 below:

06 g-i Idle NR

0b g-2 Idle NR 08 g-3 Idle NR

03 g-4 Idle NR

Table 4

The foregoing node configuration information table includes the following items: a related node ID, a corresponding HO ODUk port, a HO ODUk state, and a remote signaling. The related node ID refers to the ID of the node associated with or related to the node. For example, the related node ID in the configuration information table of the node G refers to the ID of the node associated with the node G or the adjacent node. The local action is determined by the local fault state combined with the far-end signaling state. Because the node has multiple remote directions, the remote state in each direction is stored for easy reading calculation.

Configure span protection (SP): Configure at least one protection path for each protected span, taking the FG and GK shown in Figure 5 as the protected span.

Two SPs can be configured for FG: PID#l{060a, OaOb, 0b07}, PID#2{0602, 0203,

0307}, the selection of the PID routes of the two SPs must be separated; the so-called separation refers to the path risk separation, that is, the two PID routes cannot overlap;

Two SPs can be configured for GK: PID#3{0706, 060a, OaOb} , PID#4{0708, 080c,

0c0b}, the choice of the PID routing of these two SPs must also be separated.

Configure protection identifier (PID) information on all nodes associated with it, for nodes F, J, K,

G Configure the shared mesh protection (SMP) configuration information table, and configure the SMP configuration information for node F. Table 5 shows the following table:

table 5

The SMP configuration information table configured for node J is shown in Table 6 below: PID working port PID routing (NID queue)

#1 - 06, 0a, Ob, 07

#3 - 06, 02, 03, 07

Table 6

The SMP configuration information table configured for Node K is shown in Table 7 below:

Table 7

The SMP configuration information table configured for node G is shown in Table 8 below:

Table 8

The above SMP configuration information table includes the following items: PID on the node, working port corresponding to the PID, and PID routing information.

Then, the protected services can be arbitrarily configured on the protected spanned segments, as shown in Figure 6, protected services Wl, W2, W3, and W4.

The protection switching implementation method of the embodiment of the present invention is described below by using two typical scenarios in the high-order ODU SMP. In the mesh network of the embodiment of the present invention, each span corresponds to two protection paths. There may be multiple ways to select a protection path. The method used in the first embodiment of the present invention is to find the SMP configuration information of the node, and find the first idle PID in order to use it. Scenario 1 is a single-directional fiber failure in the network.

Figure 7 shows the implementation method of selecting a PID to make a request when a single-direction fault occurs in G→F. The specific processing steps are as follows:

1. After detecting the fault of the f-3 port, the node F queries its own SMP configuration information table (that is, the foregoing Table 5), finds the PID corresponding to the f-3 port, and sequentially selects the first idle PID, that is, PID#1; Query the PID route of PID#1, find the NID of the downstream node of node F as "0a"; query the node configuration information table of node F (that is, the foregoing Table 1) to obtain the HO ODUk port corresponding to "0a" (that is, f-4) And HO ODUk status (for idle);

2. When the node F determines that the HO ODUk state of the downstream node "0a" is idle, it sends APS signaling to the APS/PCC overhead of the HO ODU of the corresponding f-4 port, and the APS signaling includes: request status (SF) ), PID (#1), T-NID of the destination node ("07"), S-NID ("06") of the source node;

3. Node J detects the APS/PCC of its HO ODU whose port j-1 (the j-1 port and the f-4 port belong to the corresponding ports at both ends of the same span, so the j-1 port corresponds to the f-4 port) The byte changes and is processed as follows:

Parsing the PID information in the APS signaling, judging the request initiated by the SP of #1; parsing the T-NID ("07"), S-NID ("06") in the APS signaling; finding its own SMP configuration information The table (ie, the foregoing Table 6) obtains the PID route of PID#1, and combines the T-NDI and S-NID information to determine that the signaling request direction is 06→0a→0b→07, and the NID of the downstream node of node J is “ 0b";

Querying the node configuration information table of the user (ie, the foregoing Table 2), and determining that the "0b" state is Idle, the APS signaling is sent to the APS/CC overhead of the HO ODU of the corresponding j-3 port, and the APS signaling includes: Request status (SF), PID (#1), T-NID of the destination node ("07"), S-NID ("06") of the source node;

4. The node K detects the HO ODU of its k-1 port (the k-1 port corresponds to the j-3 port). The APS/PCC byte changes and is processed as follows:

Parsing the PID information in the APS signaling, determining that the request is initiated by the SP of #1; parsing the T-NID ("07"), S-NID ("06") in the APS signaling; and finding its own SMP configuration information. The table (ie, the foregoing Table 7) obtains the PID route of PID#1, and combines the T-NDI and S-NID information to determine that the signaling request direction is 06→0a→0b→07, and the NID of the downstream node of node K is “ 07" ;

Querying the node configuration information table (ie, the foregoing table 3), and determining that the "07" state is Idle, the APS signaling is sent to the APS/CC overhead of the HO ODU of the corresponding k-2 port, and the APS signaling includes: Request status (SF), PID (#1), T-NID of the destination node ("07"), S-NID ("06") of the source node;

5. Node G detects that the APS/PCC byte of the HO ODU of its g-2 port (the g-2 port corresponds to the k-2 port) changes, and performs the following processing:

Parsing the PID information in the APS signaling, determining that the request is initiated by the SP of #1; parsing the T-NID ("07") and S-NID ("06") in the APS signaling; determining that the node is the APS The destination node of the request, thereby responding to the GPS port with APS signaling, including: response status (RR), PID (#1), source node S-NID ("06"), destination node T-NID ( "07" ); and node G performs local bridging/switching (Br/Sw) operation:

According to the PID route (06, 0a, Ob, 07), the local NID is "07", so the time slot of the "06" port is switched to the "0b" port;

According to the node configuration information table of node G (that is, the foregoing Table 4), "06" corresponds to port g-1, "0b" corresponds to port g-2, and performs bridging/switching operation as shown in FIG. 8;

Bridging operation: Send the local uplink to the protected port and change the port to the protection direction; send the other direction to the protected port and change to the protection direction port; other directions include the protection direction;

Switching operation: Send the protected port to the local downlink connection, change to the protection direction Port; the connection that is sent to the protected port to the other direction is changed to the protection direction port; the other direction includes the protection direction;

6. The node K detects that the APS/PCC byte of its k-2 port (the k-2 port corresponds to the g-2 port) changes, and sends APS signaling to the k-1 port, including: response status (RR) , PID ( #1 ), the T-NID of the destination node ( "06" ), the S-NID of the source node ( "07" ); and the node K performs the pass-through operation:

According to the PID route (06, 0a, Ob, 07), the local intestine is "Ob", so the time slot of the "07" port is directly passed to the "0a" port;

According to the node configuration information table of node K (ie, the foregoing Table 3), "07" corresponds to port k-2, "0a" corresponds to port k-1, and the through operation is performed as shown in FIG. 9; the through operation is to "07" The guard slots of the direction are all connected to the "0a" direction;

Straight-through operation: Establish a connection between the direct A direction and the protection time slot in the direct B direction; enable the service to pass through in the protection channel of the node.

7. Node J detects that the APS/PCC byte of its j-3 port (j-3 port corresponds to the k-1 port) changes, and sends APS signaling to the j-1 port, including: response status (RR) PID

(#1), the T-NID of the destination node ("06"), the S-NID of the source node ("07"); and the node J performs the pass-through operation:

According to the PID route (06, 0a, 0b, 07), the local NID is "0a", so the time slot of the "0b" port is switched to the "06" port;

According to the node configuration information table of node J (ie, Table 2 above), "0b" corresponds to port j-3, "06" corresponds to port j-1, and the pass-through operation connects the guard slots in the "0b" direction to "06". Direction

8. Node F detects that the APS/PCC byte of the f-4 port (the f-4 port corresponds to the j-1 port) changes, and determines that the node is the T-NID node of the request (that is, the response), and performs bridging. / Switching operation:

According to the PID route (06, 0a, 0b, 07), the local NID is "06", so to "07" The time slot of the port is switched to the "0a"port;

According to the node configuration information table of node F (that is, the foregoing Table 1), "07" corresponds to port f-3, "0a" corresponds to port f-4, and the corresponding bridging/switching operation is performed.

At this point, the protection switching operation is completed.

The traffic of the protected service W1 configured on the FG span is compared with the traffic before and after the switchover, as shown in Figure 10. The traffic of the protected service W4 configured on the FG span is compared with that before and after the switchover, as shown in Figure 11. In the protected service W3 configured on the FG span, the traffic comparison before and after the switching is as shown in FIG.

Scenario 2 is the occurrence of two single-directional fiber faults in the network.

On the basis of G→F failure, G→K also fails. It is necessary to roll back the switch caused by G→F fault to another protection link PID#2, G→K fault selection PID#4 Switching, as shown in Figure 13, the specific steps are:

1. The node K detects the alarm, and determines that the remote end of the path of PID#1 and PID#3 also has an alarm, and the k-1 port is idle (ie, returns to the initial state), and sends an SF request to the direction of PID#1, releasing PID#1. The direction is connected, and the SF request is sent to the direction of PID#4, and the PID#4 is selected to perform the fault switching of G→K;

2. Node J detects that the APS/PCC byte of its j-3 port (j-3 port corresponds to the k-1 port) changes, and sends APS signaling to the j-1 port, including: request status (SF) PID

( #1 ), T-NID of the destination node ( "06" ), S-NID of the source node ( "Ob" ); Node J judges that it has SF from both directions (ie, node F direction and node K direction) , the local idle operation is performed;

3. The node F detects that the APS/PCC byte of its f-4 port (the f-4 port corresponds to the j-1 port) changes, and sends the APS signaling to the f-3 port, including: request status (SF) PID

( #1 ), the T-NID of the destination node ("06" ), the S-NID of the source node ("Ob"); the node F determines the local channel (ie f-3 port) service SF, local far-end signaling ( That is, node K direction signaling) If it is SF, the f-4 port idle operation is performed; the node F searches its own node configuration table (that is, the foregoing Table 1), and determines that the f-1 port status is idle, then sends an SF request to PID#2, and sends APS signaling to In the APS/PCC overhead of the corresponding HO ODU of the f-1 port, the APS signaling includes: a request status (SF), a PID (#2), a T-NID of the destination node ("07"), and a S of the source node. -NID( "06"); 4. Node G detects that the APS/PCC byte of its g-4 port has changed, and performs the following processing:

Parsing the PID information in the APS signaling, determining that the request is initiated by the SP of #2; parsing the T-NID ("07") and S-NID ("06") in the APS signaling; determining that the node is the

The destination node requested by the APS, and the local g-4 port is idle, performs bridging/switching operation of the g-4 port, and responds to the g-3 signaling to the g-3 port, including: response status (RR), PID (#2) ), the S-NID of the source node ("07"), the T-NID of the destination node ("06"); If the g-2 port itself is in the reverse state, the g-2 port is released, and the g-4 port is switched. ;

5. Node C receives the RR in the direction of PID#2 and performs a straight-through operation.

6. Node B receives the RR in the direction of PID#2 and performs a straight-through operation.

7. Node F receives the RR in the direction of PID#2 and performs the switching of port f-3.

8. Node G receives the SF request in the direction of PID#4, determines that the g-3 port is idle, performs the switching of the g-3 port, and responds to the PID#4 with the RR;

9. Node H receives the RR in the direction of PID#4, performs a through operation, and sends an RR to the downstream node L.

10. Node L receives the RR in the direction of PID#4, performs a straight-through operation, and sends an RR to the downstream node K;

® and node K receive the RR and perform the switching of the k-3 port.

The business status after the switchover is shown in Figure 14.

The second embodiment still uses the high-order ODU SMP configuration information in the first embodiment. The difference from the first embodiment is that the PID selection manner is different. The selection method of the second embodiment is to two PIDs when the fault occurs. The direction requests at the same time, the destination node decides to select one of the PIDs as the response of the local request, responds to the RR (reverse request;), and the other channel answers the NR (no request;); the node that receives the RR response performs protection switching.

The implementation process of the embodiment of the present invention is described below through three scenarios.

Scenario 1 is a single-directional fiber failure in the network.

Figure 15 illustrates the process of requesting the two PID directions simultaneously to implement the switching when the G→F direction fails. The steps are as follows:

1. After detecting the fault of the f-3 port, the node F queries its own SMP configuration information table (that is, the foregoing Table 5), and finds the protection paths PID#1 and PID#2 corresponding to the f-3 port. Query the PID route of PID#1, find the NID of the downstream node of node F as "0a", and query the node configuration information table of node F (that is, the foregoing Table 1) to obtain the HO ODUk port corresponding to "0a" (that is, f-4) The APS signaling includes the request status (SF), the PID (#1), and the T-NID of the destination node ("07). " ), the source node's S-NID ( "06" ). Query the PID route of PID#2, find the downstream node NID of node F is "02", and query the node configuration information table of node F (that is, the foregoing Table 1) to obtain the HO ODUk port corresponding to "02" (that is, f-1) And the HO ODUk state (which is an idle), sends the APS signaling to the APS/PCC overhead of the HO ODU of the corresponding f-1 port, and the APS signaling includes: a request state (SF), a PID (#2), a destination node. The T-NID ( "07" ), the source node's S-NID ( "06" ). Nodes J, K, B, and C receive SF requests and continue to pass to downstream nodes.

2. If node G first detects its g-2 port (the g-2 port corresponds to the k-2 port)

The APS/PCC byte of the HO ODU changes, and the following processing is performed:

Parsing the PID information in the APS signaling, determining that the request is initiated by the SP of #1; parsing the T-NID ("07") and S-NID ("06") in the APS signaling; determining that the node is the APS The destination node of the request, thereby responding to the GPS port with APS signaling, including: response status (RR), PID (#1), source node S-NID ("06"), destination node T-NID ( "07"); And node G performs a local bridging/switching (Br/Sw) operation:

According to the PID route (06, 0a, Ob, 07), the local NID is "07", so the time slot of the "06" port is switched to the "Ob" port;

According to the node configuration information table of node G (that is, the foregoing Table 4), "06" corresponds to port g-1, "Ob" corresponds to port g-2, and performs a bridge/switch operation as shown in FIG.

Node G receives the SF request of PID#2 again, and judges that the g-1 port is already in the switching state, then responds to NR;

3. The node K detects that the APS/PCC byte of its k-2 port (the k-2 port corresponds to the g-2 port) changes, and sends APS signaling to the k-1 port, including: response status (RR) , PID ( #1 ), the T-NID of the destination node ( "06" ), the S-NID of the source node ( "07" ); and the node K performs the pass-through operation:

According to the PID route (06, 0a, 0b, 07), the local intestine is "0b", so the time slot of the "07" port is switched to the "0a" port;

According to the node configuration information table of node K (ie, the foregoing Table 3), "07" corresponds to port k-2, "0a" corresponds to port k-1, and the through operation as shown in FIG. 9 is performed; the through operation is to "07" The guard slots of the direction are all connected to the "0a" direction;

Node C receives the NR response, no switching process, and continues to send the NR to the downstream node;

4. Node J detects that the APS/PCC byte of its j-3 port (j-3 port corresponds to the k-1 port) changes, and sends APS signaling to the j-1 port, including: response status (RR) , PID ( #1 ), the T-NID of the destination node ( "06" ), the S-NID of the source node ( "07" ); and the node J performs the pass-through operation:

According to the node configuration information table of node J (ie, Table 2 above), "0b" corresponds to port j-3, "06" corresponds to port j-1, and the pass-through operation connects the guard slots in the "0b" direction to "06". Direction 5. The node F detects that the APS/PCC byte of the f-4 port (the f-4 port corresponds to the j-1 port) changes, and determines that the node is the TNID node of the request (that is, the response), and performs bridging/switching. operating:

According to the PID route (06, 0a, Ob, 07), the local intestine is "06", so the time slot of the "07" port is switched to the "0a" port;

According to the node configuration information table of node F (that is, the foregoing Table 1), "07" corresponds to port f-3, "0a" corresponds to port f-4, and the corresponding bridging/switching operation is performed. At this point, the protection switching operation is completed.

On the basis of the failure of G→F, G→K also fails. The process is shown in Figure 16. The specific steps are as follows:

1. Node K detects the k-2 port failure, queries its own SMP configuration information table (ie, Table 7 above), and finds the protection paths PID#3 and PID#4 corresponding to the k-2 port. Query the PID route of PID#3, find the NID of the downstream node of node K as "0a", and query the node configuration information table of node K (that is, the foregoing Table 3) to obtain the HO ODUk port corresponding to "0a" (that is, k-1) Sending APS signaling to the APS/PCC overhead of the HO ODU of the corresponding k-1 port, the APS signaling includes: request status (SF), PID (#3), T-NID of the destination node ("07 " ), the source node's S-NID ( "0b" ). Query the PID route of PID#4, find the downstream node NID of node K as "0c", and query the node configuration information table of node K (that is, the foregoing Table 3) to obtain the HO ODUk port corresponding to "0c" (that is, k-3). The APS signaling is sent to the APS/PCC overhead of the HO ODU of the corresponding k-3 port, and the APS signaling includes: a request status (SF), a PID (#4), and a T-NID of the destination node ("07"). ), the source node's S-NID ( "0b" );

2. The node K determines that the local remote signaling (ie, the node F direction signaling) has an SF, and the local channel (ie, the k-2 port) also has the SF, performs an idle operation, and all the connections are restored to the original state;

3. Node J detects that the APS/PCC byte of its j-3 port (j-3 port corresponds to the k-1 port) changes, and sends APS signaling to the j-1 port, including: request status (SF) PID ( #3 ), T-NID of the destination node ( "07" ), S-NID of the source node ( "Ob"); Node J judges that it has SF from both directions (ie, node F direction and node K direction) , the local idle operation is performed;

4. Node F detects that the APS/PCC byte of its f-4 port (the f-4 port corresponds to the j-1 port) changes, and sends APS signaling to the f-3 port, including: request status (SF) PID

( #3 ), the T-NID of the destination node ("07" ), the S-NID of the source node ("Ob" ); the node F determines the local channel (ie f-3 port) service SF, local far-end signaling ( That is, the node K direction signaling is also SF, and an idle operation is performed;

5. Node G detects that the APS/PCC byte of its g-1 port (the corresponding g-1 port and the f-3 port) changes, and performs the following processing:

If the content of the request in the APS signaling is resolved, and the direction of the node F and the node K are both faulty, the g-2 port is released, and the SF request suppressed by the g-4 port is released, and the g-4 port switching is performed, and the g-4 port is switched. -4 port direction response RR.

The node G detects that the APS/PCC byte of its g-3 port changes, and performs the following processing: parsing the PID information in its APS signaling, determining that the request is initiated by the SP of #4; and parsing the T- in the APS signaling. NID ("07"), S-NID ("Ob"); determine that the node is the destination node of the APS request, and the local g-3 port is idle, perform the bridging/switching operation of the g-3 port, and go to g -3 port responds to APS signaling, including: response status (RR), PID (#4), source node's S-NID ("07"), destination node's T-NID ("Ob");

6. Node H receives the RR response, performs the pass-through operation of PID#4, and continues to send the RR response to the downstream node;

7. Node L receives the RR response, performs the pass-through operation of PID#4, and continues to send the RR response to the downstream node;

8. Node K receives the RR response of the k-3 port, and performs the bridging/switching operation of PID#4. 9. Node C receives the RR response, performs the pass-through operation of PID#2, and goes to the downstream node B. Continue to send an RR response;

10. Node B receives the RR response, performs the pass-through operation of PID#2, and continues to send the RR response to the downstream node F.

(11), node F receives the RR response of port f-1, and performs the bridging/switching operation of PID#2. At this point, the protection switching operation is completed.

Scene 3 is a failure in the network.

Figure 17 shows the processing after the G→K fault disappears. After detecting that the alarm disappears, the node K first starts the recovery waiting time (WTR), and sends a WTR request to PID#3 and PID#4. After receiving the WTR request, the node G answers the RR, and the switch states of the node K and the node G are in the state of being Switch state until WTR time is up. The processing steps of WTR time are as follows:

1. When the WRT time of node K expires, query its own SMP configuration information table (ie, Table 7 above), and find the protection paths PID#3 and PID#4 corresponding to the k-2 port. Query the PID route of PID#3, find the NID of the downstream node of node K as "0a", and query the node configuration information table of node K (that is, the foregoing Table 3) to obtain the HO ODUk port corresponding to "0a" (that is, k-1) And sending APS signaling to the APS/PCC overhead of the HO ODU of the corresponding k-1 port, the APS signaling includes: request status (NR), PID (#3), T-NID of the destination node ("07 " ), the S-NID of the source node ( "Ob" ). Query the PID route of PID#4, find the downstream node NID of node K as "0c", and query the node configuration information table of node K (that is, the foregoing Table 3) to obtain the HO ODUk port corresponding to "0c" (that is, k-3). The APS signaling is sent to the APS/PCC overhead of the HO ODU of the corresponding k-3 port, and the APS signaling includes: a request status (NR), a PID (#4), and a T-NID of the destination node ("07"). ), the S-NID of the source node ( "0b" );

2. Node L receives the NR of PID#4, performs idle, and responds to NR;

3. Node H receives the NR of PID#4, performs idle, and responds to NR;

4. Node G detects that the APS/PCC byte of its g-3 port changes, and performs the following processing: Parsing the PID information in the APS signaling, determining that the request is initiated by the SP of #4; parsing the T-NID ("07") and the S-NID ("Ob") in the APS signaling; determining that the node is the APS The destination node of the request, if there is no request, releases the g-3 port and responds to the g-3 port with the APS signaling, including: response status (NR), PID (#4), S-NID of the source node ( "07"), the T-NID of the destination node ("Ob");

5. Node J receives NR, no processing;

6. Node F receives NR and has no processing.

At this point, the PID#4 link resource is released.

The present invention also provides an embodiment of a network protection system, including: an end node on a protected span, an intermediate node on a protection path, as shown in FIG. 18, where

An end node 81 located downstream of the signal stream on the protected span, configured to detect at least one protection path along the protected span according to configuration information of the end node when detecting that the protected span fails Send automatic protection switching APS request signaling;

The end node 82 located upstream of the signal stream on the protected span is configured to send APS response signaling along the corresponding protection path after receiving the APS request signaling, and the end node located upstream of the signal flow according to itself The configuration information performs the corresponding bridging/switching operation;

The intermediate node 83 receiving the APS response signaling is configured to perform a corresponding through operation according to the respective configuration information;

The end node 81 located downstream of the signal stream that receives the APS response signaling is configured to perform a corresponding bridging/switching operation according to its own configuration information.

Preferably, when the end node 81 located downstream of the signal stream sends the APS request signaling along the multiple protection paths of the protected span, the end node 82 located upstream of the signal flow is configured to select the protection path for performing the protection switching. And the APS response signaling sent along the selected protection path carries the reverse request RR, and the APS response signaling sent along the unselected protection path carries the unsolicited NR.

The SMP configuration information table includes: a protection identifier PID, a working port, and a PID route. Preferably, the end node 81 located downstream of the signal stream on the protected span is further configured to, when detecting that the fault of the protected span disappears, initiate a recovery wait time WTR, and along the protected span At least one protection path sends a WTR request; after receiving the WTR request, the end node 82 located upstream of the signal stream on the protected stride answers the RR, and the end node 82 located upstream of the signal stream and the end node 81 located downstream of the signal stream are Switch state until WTR time is up;

When the WTR time expires, the end node 81 located downstream of the signal stream sends an APS request signaling carrying the NR along the at least one protection path of the protected span according to its configuration information, as the protected cross The node that receives the APS request signaling carrying the NR on the protection path of the segment execution protection releases the corresponding port idle and answers the NR.

The mesh protection of the embodiment of the present invention is applicable to at least the following scenarios: mesh protection based on optical channel (OCH, Optical Channel), and mesh protection based on Optical Multiplexer (OMS). Industrial applicability

In summary, the embodiment of the present invention can improve the protection switching performance of the mesh network, strengthen its anti-fault capability, and at least resist two pipeline failures.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

claims

1. A mesh protection method, including:

When the end node located downstream of the signal flow on the protected span detects that the protected span fails, based on the configuration information of the end node, it sends automatic protection switching along at least one protection path of the protected span. APS request signaling;

After receiving the APS request signaling, the end node located upstream of the signal flow on the protected span sends APS response signaling along the corresponding protection path, and the end node located upstream of the signal flow executes according to its own configuration information. Corresponding bridging/switching operations; The intermediate nodes that receive the APS response signaling perform corresponding pass-through operations according to their respective configuration information; The end nodes located downstream of the signal flow that receive the APS response signaling perform according to their own configuration information Perform corresponding bridging/switching operations.

2. The method of mesh protection according to claim 1, wherein when the end node located downstream of the signal flow sends APS request signaling along the multiple protection paths of the protected span, the end node located upstream of the signal flow Select a protection path to perform protection switching, and the APS response signaling sent along the selected protection path carries reverse request RR, and the APS response signaling sent along the unselected protection path carries no request NR.

3. The method of mesh protection according to claim 2, wherein before detecting the fault, the method further includes:

Configure respective node configuration information tables for the nodes in the mesh network. The node configuration information table includes: related node ID, corresponding high-order optical data unit HO ODUk port, corresponding HO ODUk status, and remote signaling;

Configure cross-segment protection for the mesh network, configure at least one protection path for each protected span, and configure a shared mesh protection SMP configuration information table for nodes in the mesh network. The SMP configuration information table includes: Protection identification PID, working port and PID routing;

The configuration information includes the node configuration information table and the SMP configuration information table.

4. The mesh protection method according to claim 1, 2 or 3, wherein the method further includes: in the HO ODU of each span in the mesh network, half of the time slots are allocated as protected resources, and the other half are allocated as protected resources. Slots are allocated as protection resources.

5. The method of mesh protection according to claim 1, 2 or 3, wherein the APS request signaling and APS response signaling are transmitted through the APS or protection communication channel PCC overhead of HO ODUk.

6. The mesh protection method according to claim 1, 2 or 3, wherein when an end node located downstream of the signal flow on the protected span detects that the fault of the protected span disappears, the end node Start the recovery waiting time WTR, and send a WTR request along at least one protection path of the protected span. After receiving the WTR request, the end node located upstream of the signal flow on the protected span responds with RR, which is located upstream of the signal flow. The end node and the end node located downstream of the signal flow are in the switching state until the WTR time expires;

When the WTR time expires, the end node located downstream of the signal flow sends APS request signaling carrying NR along at least one protection path of the protected span according to its own configuration information, which is the protected span. The node on the protection path that performs protection and receives the APS request signaling carrying the NR releases the corresponding port to be idle and responds to the NR.

7. A mesh protection system, including: end nodes on the protected span and intermediate nodes on the protection path, where,

The end node located downstream of the signal flow on the protected span is configured to, when a failure of the protected span is detected, send along at least one protection path of the protected span according to the configuration information of the end node. Automatic protection switching APS request signaling;

The end node located upstream of the signal flow on the protected span is configured to send APS response signaling along the corresponding protection path after receiving the APS request signaling, and the end node located upstream of the signal flow is configured to send APS response signaling according to its own Configuration information performs corresponding bridging/switching operations;

The intermediate node that receives the APS response signaling is configured to execute according to the respective configuration information. Corresponding pass-through operation;

The end node located downstream of the signal flow that receives the APS response signaling is configured to perform corresponding bridging/switching operations according to its own configuration information.

8. The mesh protection system according to claim 7, wherein when the end node located downstream of the signal flow sends APS request signaling along the multiple protection paths of the protected span, the end node located upstream of the signal flow The configuration is to select a protection path for performing protection switching, and the APS response signaling sent along the selected protection path carries the reverse request RR, and the APS response signaling sent along the unselected protection path carries the no request _NR .

9. The mesh protection system according to claim 7, wherein the configuration information includes a node configuration information table and an SMP configuration information table,

The node configuration information table includes: relevant node ID, corresponding high-order optical data unit HO ODUk port, corresponding HO ODUk status, and remote signaling;

The SMP configuration information table includes: protection identification PID, working port and PID route.

10. The mesh protection system according to claim 7, 8 or 9, wherein in the HO ODU of each span in the mesh network, half of the time slots are allocated as protected resources, and the other half of the time slots are allocated as protected resources. .

11. The mesh protection system according to claim 7, 8 or 9, wherein the APS request signaling and APS response signaling are transmitted through the APS or protection communication channel PCC overhead of HO ODUk.

12. The mesh protection system according to claim 7, 8 or 9, wherein the end node located downstream of the signal flow on the protected span is further configured to, when detecting that the fault of the protected span disappears, Start the recovery waiting time WTR, and send a WTR request along at least one protection path of the protected span; after receiving the WTR request, the end node located upstream of the signal flow on the protected span responds with an RR, which is located upstream of the signal flow. The end node and the end node located downstream of the signal flow are in the switching state until the WTR time expires; When the WTR time expires, the end node located downstream of the signal flow sends APS request signaling carrying NR along at least one protection path of the protected span according to its own configuration information, which is the protected span. The node on the protection path that performs protection and receives the APS request signaling carrying the NR releases the corresponding port to be idle and responds to the NR.